Highway trailers of conventional design are generally provided with hinged doors at the rear of the trailer which are pivotally mounted to be swung open and allow the doors to lie along the sides of the trailer. The doors are then fastened along the side of the trailer to allow the trailer to be maneuvered up to a loading dock or otherwise positioned for unloading.
It is important under these circumstances that the doors be held as tightly as possible against the side of the trailer. If a door protrudes unduly, it may catch on structures adjacent to the loading dock. In the past doors have been secured by providing a link from the door extending to a hook or other latch secured to the sidewall of the trailer. The link is typically in the form of a length of chain. Such chains are commonly anchored at one end by being fastened to the door by door hardware. The other end, the free end, is then attached to the hook on the trailer side.
It is desirable that the receiving hook be positioned on the side of the trailer at the same height as the location of the anchor point on the trailer door. This provides the chain with the shortest path in extending between the anchor point and the hook. This in turn holds the open door as closely as is practical to the side of the trailer.
The hook itself may be mounted at various heights along the side of the trailer, depending on the stability of the trailer wall. For example, a floor beam or vertical wall beam on the trailer side wall is the preferred site for attaching the receiving hook. However, at the anchor end (i.e. on the door), conventional mounting brackets generally restrict the chain anchor point to a single position. That anchor point may not be compatible with providing the chain with the shortest path when extending between the anchor point and the hook.
U.S. Pat. No. 6,478,348 discloses a hook with a security feature for receiving a chain used to hold the door of a highway trailer open. A plate member is affixed to a support, adjacent the vertical side edge of the door in either the open or closed position. The plate is provided with a receiving hook and a pivotally mounted bail intermediate the ends thereof. The chain is secured to the vertical side edge of the door and is passed upwardly through the bail and the end is slipped over the end of the finger member, which is then allowed to fall back to its rest position and thereby secures the door in the selected open or closed position.
U.S. Pat. No. 5,273,326 discloses a door hold back device with a link having spherical end portions is connectable between a socket provided in a mounting plate on the vehicle wall and a socket provided in a receiver on the cargo door.
U.S. Pat. No. 4,269,439 discloses a door holdback device that may be mounted on the wall of a highway trailer and is automatically retractable to an inoperative position. The device has a primary wire loop extending from the wall that is integrally attached to two secondary wire loops, which are then secured to the interior of the wall. The secondary wire loops are internally stressed to retract the primary loop when not in use.
U.S. Publication No. 20090033106 discloses a door holdback device (or bracket) that is mounted on a supporting surface. The device includes housing and an enclosed post that extends upward from a base. The housing has an opening which allows a loop on a rope to be installed over the post by inserting the loop through the opening.
There is a need for a mounting system for a chain bracket that improves the prospects for mounting the hook and chain anchor at optimal locations on the trailer body. In particular, it would be desirable to provide a bracket mounting system minimizing the chain length employed to secure the doors in an open position.
While this device will be described with particular reference to transport vehicles, such as semi-trailer or truck body doors, it will be appreciated by those skilled in the art that such a device finds application at other locations, where door and gate holdbacks or latches are used to secure swing-able gates or doors in an open or closed position.
The device in its general form will first be described, and then its implementation in terms of specific embodiments will be detailed with reference to the drawings following hereafter. These embodiments are intended to demonstrate the principles of the device, and the manner of its implementation. The device in its broadest and more specific forms will then be further described, and defined, in each of the individual claims which conclude this specification.